1. Field of the Invention
The present invention generally relates to the conversion of the supporting structure for an intermediate gear in a gear box or transfer case from a structure utilizing loose needle bearing assemblies for supporting the intermediate gear rotatably on a shaft anchored to the transfer case to a tapered roller bearing assembly rotatably supporting the intermediate gear from a bolt-type shaft anchored to the transfer case without any mechanical modification of the transfer case with the same lock plate being used to retain the tapered bearing assembly and bolt-type shaft in place in the transfer case to enable the conversion to be completed without requiring any machine work or other modification to the transfer case.
2. Disclosure Statement
In many commercially available vehicles, especially four wheel drive vehicles, the intermediate gear in the gear box or transfer case is supported from the intermediate shaft by loose needle bearings with the internal bore of the intermediate gear serving as an outer race for the needle bearings and the external surface of the intermediate shaft serving as an inner race for the needle bearings. This arrangement creates a large bearing surface resulting in unnecessary friction and noise at high RPM and also results in considerable wear of the needle bearings themselves, the inner race (the external surface of the intermediate shaft) and the outer race (the internal bore of the intermediate gear) thereby resulting in an expensive replacement. This problem is especially significant when such vehicles are used over roadways and the like at relatively high speeds.
Also known are various types of bearing structures to support two components rotatably in relation to each other. Many installations utilize oppositely disposed tapered roller bearings with a retaining nut to retain the bearings in place and tighten the bearings to a predetermined degree. The following U.S. patents disclose tapered roller bearing assemblies for various purposes and constitutes the prior art known to applicant.
U.S. Pat. No. 2,407,532--Sep. 10, 1946--Boden
U.S. Pat. No. 2,826,466--Mar. 11, 1958--Pritchard
U.S. Pat. No. 3,716,280--Feb. 13, 1973--Leibensperger et al.
U.S. Pat. No. 3,804,477--Apr. 16, 1974--Allmandinger et al.
U.S. Pat. No. 3,896,684--July 29, 1975--Duer
U.S. Pat. No. 3,915,032--Oct. 28, 1975--Ottemann
U.S. Pat. No. 3,929,036--Dec. 30, 1975--Shealy
U.S. Pat. No. 4,023,868--May 17, 1977--Miki
U.S. Pat. No. 4,061,377--Dec. 6, 1977--Nordstrom
Even though various bearing arrangements are known to support one member rotatably in relation to another, to-date, the only solution to the problems occurring with respect to rotatably supporting an intermediate gear in a transfer case in the types of vehicles mentioned above has been the replacement of the components with similar components, that is, the replacement of the worn needle bearings, intermediate gear and intermediate gear shaft with new components of the same type.